//時間計測用
//構築未実装
#include <iostream>
#include <stdio.h>
#include <vector>
#include <algorithm>
#include <assert.h>
#include <stdlib.h>
#include <memory.h>
#include <queue>
#include <time.h>
#include <chrono>
#include <sys/time.h>
#include <atcoder/maxflow>
using namespace std;
using namespace atcoder;
#define ll long long
#define INF 1000000000000000000
using std::cout; using std::endl;
using std::chrono::duration_cast;
using std::chrono::milliseconds;
using std::chrono::seconds;
using std::chrono::system_clock;


int main(){
  auto start = duration_cast<milliseconds>(system_clock::now().time_since_epoch()).count();
  ll N,A,B;
  cin>>N;
  //Dinic F(200002);
  //Dinic F;
  //cout<<"INF:"<<F.INF<<endl;
  mf_graph<ll> F(200010);
  for(int i=0;i<N;i++){
    //cerr<<i<<endl;
    cin>>A>>B;
    A--;B--;
    /*
    F.add_edge(200000,i,1);
    F.add_edge(i,100000+A,1);
    if(A!=B)F.add_edge(i,100000+B,1);
    F.add_edge(100000+i,200001,1);
    */
    F.add_edge(200000,i,1);
    F.add_edge(i,100000+A,1);
    if(A!=B)F.add_edge(i,100000+B,1);
    F.add_edge(100000+i,200001,1);
  }
  //cerr<<"edge added\n";
  //ll cnt=F.max_flow(200000,200001);
  ll cnt=F.flow(200000,200001);
  //cout<<cnt<<endl;
  if(cnt!=N){
    cout<<"No\n";
    return 0;
  }
  //ここから構築
  cout<<"Yes\n";
  auto end= duration_cast<milliseconds>(system_clock::now().time_since_epoch()).count();
  cerr<<end-start<<endl;
  return 0;
}